The several objectives of this research include studies of the cell-free biosynthesis of the oral antibiotics griseofulvin, tetracycline and penicillin, and the C13-labeled study of the biosynthesis and structure of the anti-tumor antibiotic hedamycin. Another objective is the development of models for polyketide biosynthesis including tetracycline and aflatoxin as ultimate target molecules. A new theory for penicillin and cephalosporin biosynthesis will be tested via laboratory model studies. This work will lead to a deepening of our understanding of the biosynthetic pathway for many classes of natural product structures. BIBLIOGRAPHIC REFERENCES: "Acetyl Transfer Reaction in Catechol Acetate Malonate: A Model for the Biosynthesis of Polyketides and Fatty Acids," A. Ian Scott, C.J. Wiesner, S. Yoo, Sung-Kee Chung, J. Amer. Chem. Soc., 97, 6277 (1975). "A Novel Rearrangement of 4-Dedimethylamino-4-Keto-5a, 6-Anhydrotetracycline," A. Ian Scott, Elaine Yamaguchi and Sung-Kee Chung, Tetrahedron Letters, 16, 1369 (1975).